1910-1913: Exports account for 18 percent of Germany's GDP, and Germany is the number two exporter at the turn of the century. Industrial cartels influence foreign trade, while tariffs protect primary goods in particular from foreign competition.

1914-1918: British blockades and German U-boats hamper shipping and make trade difficult.

1919-1932: Exports decline to 15 percent of GDP in the late '20s. Foretelling the Nazi goal for self-reliance, Hitler writes in "Mein Kampf," "[W]e are finally putting a stop to the colonial and trade policy of the prewar period and passing over to the territorial policy of the future."

1933-1944: The Nazi regime aims for economic self-sufficiency (autarchy) through industrial policy and bartering for raw materials with nearby states. The shift away from trade-oriented growth, together with the global depression, contributes to a fall in trade to only 6 percent of GDP in the late '30s. Once war begins, occupied territories are exploited for raw materials and labor.

1945-1949: The occupation government reverses Nazi policies of economic self-sufficiency, but the ruined infrastructure and halting economy throughout Europe limit opportunities for trade. The Marshall Plan helps reintegrate Germany into the slowly reviving European economy.

1950-1956: Germany joins the European Coal and Steel Community, a free-trade arrangement that will develop into the European Union. Increasingly open trade in Europe and the world helps Germany's rapidly growing export economy. A long period of consistent trade surpluses begins.

1957-1970: Germany helps found the European Economic Community through the Treaty of Rome in 1957, boosting Germany's export economy. Germany's famed engineering prowess allows production of high-quality manufactured exports that drive the economic miracle. Exports rise from 17 percent of GDP to 24 percent in 1970; trade surpluses will persist until 1990.

1971-1980: Exports rise slightly to 27 percent in 1980. But the oil shocks strain the balance of payments through the effect of oil imports and negative impacts on domestic industry such as steel. The first signs that some of Germany's traditional sectors such as machinery and chemicals may be losing competitiveness are met with subsidies.

1981-1990: Germany enjoys big trade surpluses during the second half of the decade, briefly becoming the world's largest exporter. The economy is increasingly tilted towards services, but Germany's manufacturing industry remains important.

1991-1999: Following reunification with the East, Germany has big trade deficits. Globalization raises fears that Germany's core exports - steel, machinery, chemicals -- can be made cheaper elsewhere, and Germany will not be able to keep ahead in a high-technology-driven global economy. Complex safety laws are an often unintended barrier to foreign goods.

2000-2003: Germany registers a trade surplus, thanks in part to some export gains, but mostly to a drop in imports resulting from the persistent weakness of domestic demand. The rise of the euro against the dollar in 2002-03 makes German exports more expensive and sparks fears the surplus may be short-lived.